User picker for Request Participants cannot find a user with a very short name when there are other users that have their name somewhere as part of their name or username

Issue Summary

User picker in the "Request participants" field can't find the user by their email address (or any other attribute) when the user has a very short name, as described in https://jira.atlassian.com/browse/JRASERVER-69836 and https://jira.atlassian.com/browse/JRASERVER-65142

Expected Results

Find the user at least by their email address

Actual Results

The user can't be found due to less relevant users showing up in higher in the search results.

Workaround

Change user email to include a custom tag. E.G. User Ha Ha with email address ha.ha@example.com is not searchable by their full email due to the fact that current Jira implementation of user search treats both the "." and "@" characters as search terms dividers, and search results are limited to 20 and ordered alphabetically. Changing the user email to "ha.ha+jira@example.com" will make them searchable through "ha+jira" term. The emails will arrive to their inbox tagged with "jira" label. The tag can be any word of your choosing, however, people sharing the request will have to know it to be able to search for the user.

For resolution of the issue, please refer to Jira tickets JRASERVER-69836 and JRASERVER-65142